• Activity patterns of some inshore fishing vessels in 2006-2007

      Fahy, E.; Fee, D.; O'Connor, S.; Smith, T. (Marine Institute, 2007)
      Observations of daily “absence-from-port” patterns and indications of gears used were carried out on 147 vessels ranging from 5 to 13 m overall length, between April 2006 and March 2007 at three ports in west, southwest and southern Ireland. The vessels numbered approximately 6% of the total national fleet and they were larger than the average length of boats observing a daily working “absence-from-port” pattern. Fishing gears belonged to one of five categories: shellfish dredges, nets, hook and line, pots and otter trawl. More than half of the vessels observed did not carry any indication of fishing gear; 46 % had evidence of using one gear and 3% showed signs of using two. Activity (absence) patterns were low, ranging between 14 and 42 % of week-days on which observations were made. The annual pattern of gear usage described by BIM in 1999 was not apparent in any of the three ports. Instead, the local availability of fishing opportunities was influential in deciding which methods predominated. In only one port was there a marked seasonal activity pattern. Visible signs of vessel registration were similar to the situation in 2002.
    • Validation of Standard Weights and Raising Coefficients for Discard Estimation: Report of a Survey Aboard MFV Roisin Bairbre

      Smith, T.; Comerford, S.; Officer, R. (Marine Institute, 2007)
      This survey was carried out to verify the Marine Institute's discard sampling protocol and the standard weights and conversion factors used when calculating discard rates. The MFV Roisin Bairbre was chartered to fish as normal on the Aran Prawn Grounds using twin rig prawn gear. The entire bulk catch was weighed, as well as the entire retained catch, thereby getting an accurate rate of discarding for this trip, as well as accurate individual basket weights. Retained catch was also weighed by species prior to and after gutting, to check the raising factors used when changing gutted landings back to round. This survey showed that the rate of discarding for this trip was 62% of the total bulk catch. There was no significant difference between the measured bulk catch weighed and the estimated bulk catch derived from using the standard weights. This validates the standard weights used. There was no significant differences between the observed conversion factors (from gutted to whole weight) and those currently used routinely in weight conversions. A standard weight for big baskets of bulk catch on a fish directed trip of 34.5 kg, and 28kg for a Nephrops directed trip were achieved.